Floor surfacer



Juhe 1 ,1926. 1 581 1 .1-

' W. A. LACY FLOUR, SURFACER Filed Oct. 10. 1923 3 Sheets-Sheet 1 J, J 7, I A /3 .f/ 6554 ATTORNEY.

' June 1 1926.

W. A. LACY FLOOR SURFACER Filed Oct. 10, 1923 5 Sheets-Sheet.2

- INVEN TOR.

" A TTORNEY.

June 1 1926. 1,587,124

W. A. LACY FLOOR SURFACER Filed Oct. 1Q, 1923 s Sheets-Sheet 5 ATTORNEY.

Patented June 1, 1926.

UNITED STATES WILLIAM LACY, 01F SPRINGFIELD, MASSACHUSETTS.

FLOOR SURFACEB.

Application filed October 10, 1923. Serial No. 667,645.

My invention relates to improvements in power-driven machines for work on floor surfaces, and consists generally of a casing or frame having an electric motor located inside thereof, driving and supporting rollers, means to drive said rollers from said motor, an endless band or belt driven by and supported on said rollers, and adapted to receive and carry with it a sandpaper or other abrading-material belt, or a polishing belt, adjusting means for one of said rollers whereby the tension on said first-named belt may be increased or decreased, adjustable means for either said sandpaper or polishing belt whereby the tension thereon may be increased or decreased, and'yielding or resilient means to force the belts onto or maintain them on the floor between the bottom rollers, all of special and peculiar construction and arrangement and combined in a new and novel manner, together with such other parts and members as may be necessaryor desirable in order to render the'machine complete and serviceable in every respect, as hereinafter set forth.

One object of my invention is to produce a comparatively inexpensive, compact, convenient, and easily handled floor surfacer, which is motor-driven but manually controlled and guided, for smoothing flooring to remove unevcnnesses therefrom, and to polish flooring covered with wax or other polishing material. Heretofore machines of this character have been too heavy and cumbersome to be transported and operated to the best advantage, and especially by one man, while my machine is essentially a one-man machine, although, of course, it might be made so large and heavy as to require the services of an additional man or men to handle the same.

Another object is to provide a machine of this character which is capable of removing paint from, smoothing, or polishing practically the entire surface of a floor, inasmuch as such machine can be operated effectually to within a small fraction of an inch of the base-boards. This is a most important advantage not possessed by the old machines.

Still another object is to produce a surfacing machine which is readily convertible from a roughing surfacer to a polishing surfacer and vice versa.

A further object is to afford in the maprove the balance of the same, whereby the manipulation and operation thereof arematerially facilitated.

Other objects and advantages will appear in the course of the following description.

A preferred embodiment of the invention,

whereby I obtain-the objects and secure theadvantages of the same, is illustrated in the accompanying drawings, and I will proceed to describe the invention with reference to said drawings, although it is to be understood that the form, construction, arrangement, etc. of the parts in various aspects are not material and may be modified without departure from the spirit of mv invention. y

In the drawings, in which like numerals designate like parts throughout the several views, Figure l is a top plan of a floor surfacer which embodies a practical form of my invention as aforesaid, a portion of the belt carrier being broken away to disclose the parts below, and portions of the tension and guiding roller, for the floor-surfacing (abrading or polishing) belt, and the hearing at one end of said roller being broken away; Fig. 2, a front side elevation of said floor surfacer showing one of the floor-.

surfacing belts in place; Fig. 3, an approximately central, vertical, longitudinal section through the surfacer, looking from within, toward the front side thereof, said belt also being in place in this view, but a portion of the driving strip at the bottom being broken out; Fig. 4c, a top plan of one of the cushion or tension plates or shoes for the carrier and belt; Fig. 5, a transverse, vertical section through the bottom portion of the frame of the surfacer, and through certain parts and members located in that portion of the surfacer; Fig. 6, a front elevation of the handle showing the same attached to a fragmentary portion of the body of the surfacer, intermediate portions of said handle and of the wires being detail, taken on lines 7-7, looking down, in

.the plates 1 and 2 to receive contiguous through the side plates and being tapped let into side plates in .precisely the same manner that the ends of the upperfront rod are let into the bars 9, and the screws 4 for the plate rods are tapped into said rods and have their heads countersunk in said plates just as in the other case.

A very rigid and substantial frame is thus constructed for the machine. The screws 4 securely hold together the plates 1 and 2 and the plate 3, and said first-named plates broken out; Fig. 7, an enlarged, sectional Fig. 2, and, Fig. 8, a sectional detail taken on lines 88 looking toward the left, in Fi 2.

in the following description it is to be assumed that the side of the machine presented in Fi 2 is the front side, and that the left an right-hand endsof the machine as presented in Figs. 1 and 2 are respectively the front and r ar endS- and the rods 12, the upper front rod acting The frame f hi flOOT-SIIIfE'JQI 1 19 1 through the bars .9 which have only endwise vertical, fIOIlt and back side plates 1 and 2'. move nent in aid,v plates The stability respectively, and a horizontal, bottom or rigidit nd ecurity of the frame are augfloor plate 3 which extends be we n Sald mented by grooving and recessing the side first-named plates, and has its front and plates and bars to receive the contiguous back side edges let into the same in the mand es d d of th fl o l t d th ner shown in Fig. 5. The plate 3 is secured m in place, in grooves which are provlded m E h f th l t 1 d 2 h a recess 13 in the upper part of the face thereof, which recess opens through the top of the plate, and extending into such recess is a horizontal stud 14. A handle 15 is provided atone terminal with arms that are receivable at their free ends in the recesses 13, and perforated to receive the studs 14, one of such arms appearing at 16 in Fig. 6. By means of the handle 15 the machine is manually guided and held against the forward driving or propelling action of the operatin parts and members, as will appear more fu ly hereinafter. The handle can be rocked freely on the studs 14, and thus capable of meeting the requirements incident to the proper manipulation and control of the machine. The arms (16) are resilient to enable them to be sprung into and out of engagement with the studs 14.

The outer face or surface of the rear plate 2 is entirely plain, or, in other words, there are no projections, not even including the rear stud 14 and arm 16, beyond the plane of said surface, consequently the machine can be operated with said plate against a base-board.

Located within the frame of the machine on the floor plate 3 and bolted thereto is an electric motor 17. This motor is entirely within and its weight is carried very close to the bottom of the frame. Preferably the axis of the motor 17 should be located in front of the transverse, vertical, central plane of the frame, and said motor might be located to advantage even nearer to the front end of the frame than is shown in the drawings. Thus the motor is entirely out of the way, andlends itself to the proper balancing of the surfacer, tending always to counteract the tendency of said surfacer to raise its front end off of the floor, and to retain the surfacer fiat on the floor.

The motor 17 has a shaft 18 on the front end of which is secured a pinion 19.

Loosely mounted on the rods 12 between the plates 1 and 2 are four rollers 20. These edges of said first-named plate, by means of three screws 4 on a side, sald screws passing into the bottom plate. The heads of the screws 4 are countersunk in the plates 1 and 2. The plate 3 is located a short distance above the bottom edges of the side plates 1 and 2, and does not extend as far as the ends of said side plates. The front and rear ends of the plates 1 and 2 converge slightly from the bottom upwardly, and said front ends near the top have quite a sharp inclination rearwardly, as represented at 5. In each of the plates 1 and 2 near the top is a horizontal slot 6 which opens through the inclined part 5 of the front edge of such plate, and a bar 9 is arranged to slide in said slot. the longitudinal edges of said bar being rabbeted into the contiguous edges of the slot. The two bars 9 are rigidly connected by means of a pair of rods 10 and a pair of nuts 11. Each rod 10 has a head at one end which is countersunk in the rear bar 9, and said rod, after passing through said bar and the front bar 9, receives one of the nuts 11 on the opposite terminal thereof, such terminal being screw-threaded to accommodate said nut. A rod 12 extends between the bars 9 adjacent to their forward terminals, which terminals have inclinations to correspond with the inclined parts 5, and said rod is secured in place by means of two additional screws 4. Each end of the rod 12 is let into the contiguous bar 9, and one of the screws 4 is tap ed into such end after passing through said bar, the head of said screw being countersunk in the bar see Fig. 8. Three similar rods are similarly connected with the plates 1 and 2, two of them being adjacent to the bottom and front and rear edges of said plates, and the other being adjacent to the top and rear edges thereof. Six additional screws 4 are employed with the last-mentioned three rods 12. The ends of the said three rods 12 are rollers 20 may or may not be provided with ate of the ends, or in the same vertical plane,

with said gear and the other two grooves.

,An endless belt carrier 24 is -mounted on the rollers 20, and on the inside of said carrier midway between the edges thereof is a flexible driving member or strip. 25 having teeth to engage the teeth of the gear 22. The driving strip 25 is riveted or otherwise secured to the belt carrier 24. The grooves 23 in the upper front and bottom rollers 20 are for the accommodation of the strip 25. This driving strip with its teeth may be made of leather, fiber, or other suitable material. The width ofthe carrier 24 is equal to the distance between the plates 1 and 2. Preferably the carrier 24 is made of rubber the outer surface of which is corrugated or otherwise indented or roughened. The upper rear roller 20 is provided at the front end inside of the plate 1 with a second gear 26, and said gear and roller are driven from the motor pinion 19 through a train of gears loosely mounted on studs 27 and 28 set in said plate and secured thereto on the outside by means of a pair of nuts 29. A large gear 30 and a small gear 31 connected to revolve together are loosely mounted on the stud 27, and a small gear 32 is loosely mounted on the stud 28. The

1 gear 30 intermeshes with the pinion 19, the

gear 32 intermeshes with the roller gear 26, and said gear 32 and the gear 31 intermesh with each other. The roller 20 which is equipped with the gear 26 is driven from the motor 17, through the medium of the pinion 19 and gears 30, 31, 32, and said firstnamed gear, and said roller, through the medium of its gear 22 and the driving strip 25, actuatesthe belt carrier 24 in the direction of the associated arrow in Fig. 2.

. The four rollers 20, including with the upper rear roller the gear 26, extend clear across the space between the plates 1 and 2. Inasmuch as the upper front roller 20 is mounted on the rod 12 which is supported by and rigidly connected with the bars 9, said roller can be moved outwardly and inwardly, for the purpose of increasing or decreasing the tension on the belt carrier 24, by sliding said bars in thecorresponding direction in their slots 6. To effect this adjustment a ratchet-wheel 33, a pawl 34, a cam 35, and a block 36 are provided. A horizontal shaft 37 is journaled in the side plates 1 and 2, directly behind the rods 10, and the ratchet-wheel 33 and the cam 35 are mounted on and secured to said shaft, said cam being in the center and said ratchet-wheel being adjacent to the front end of said shaft. The shaft 37 projects beyond the plate 1, just inside of which the ratchet-wheel 33 is located, and a knob 38 is secured to the protruding terminal of said shaft outside of said plate. The block 36 is secured to the rods 10 in front and in the path of the cam. The block 36 has a rounded end for contact therewith of the cam 35. The pawl 34 is mounted on a spindle 39 which is journaled in the plate 1 and provided at the outer end with a knob 40, said pawl being inside and said knob being outside of said plate. The pawl is in position to engage the ratchet-wheel 33, and a spring 41 retains said pawl in such engagement. The spring 41 is attached to a pair of studs 42 that project inwardly from from the plate 1.

Upon rotating the knob 38 in the direction of the associated arrow in Fig. 2, the shaft 37 and cam 35 are rotated in the same direction and said cam then forces the block 36 forwardly. The forward movement thus imparted to the block 36 is also imparted to the rods 10, the bars 9, the rod 12 carried by said bars, and the roller 20 carried by said last-named rod. Such movement of the upper front roller increases the tension on the belt carrier 24. The ratchet-wheel 33 at this time clicks past the spring-pressed pawl 34, but is held by said pawl against rotation in the opposite direction as soon as the knob 38 is released. By means of the pawl 34, therefore, the tension placed on the carrier 24 is maintained. To decrease such tension or release the carrier 24 so that the same can be removed from the machine, it is necessary to grasp both knobs 38 and 40,'and first rotate the knob 38 in the direction ofthe associated arrow far enough to permit the pawl 34 to be released from the ratchet-wheel 33, and then partially rotate the knob in the direction to rock said pawl to the left, through the medium of the spindle 39, out of engagement with said ratchet-wheel. The cam 35 is now rotated, either by hand or by the pressure exerted thereon by the carrier 24 through the medium of the intervening parts and members, in the direction to present the low part of said cam to the block 36, when said block and the rods 10 and connected bars 9 are permitted to move inwardly or rearwardly carrying with them the upper front rod 12 and roller 20. When the upper front roller 20. is in fully retracted position, the carrier 24 can be removed and replaced with the utmost facility.

The belt carrier 24 travels evenly on the four rollers 20, from the upper rear one of which said carrier is driven, and in passing under the lower rollers 20 said carrier passes below the horizontal plane of the bottom edges of the plates 1 and 2. This is due to the fact that the peripheries of the lower rollers 20 are tangent to the plane of the bottom edges of the front and back. plates. These rollers are respectively in front of and behind the floor plate 3/ Each plate 1 and 2 has an opening 43 therein to afford access to the interior of the frame, and projecting beyond the front edge of such opening in the front plate is a perforated guide 44. At and 47 are represented wires that form a circuit from the source of electric energy, through the motor .17, back to such source. The wires 45 pass from the motor through the guide 44 to the handle 15. The handle 15 is made hollow. or has a passage therethrough, and is provided adjacent to its outer end with an electric switch 46. The wires 45 enter the handle 15 at the inner end thereof, and extend through the same to the switch 46, and the wires 47 enter said handle at the outer end and pass to said switch. Upon partially rotating the switch 46 in one direction the electric current is permitted to pass to and through the motor 17, over the circuit established by the wires 47, the switch 46, and the wires 45. When the switch 46 is partially rotated in the opposite direction the current is cut off from the motor.

An endless floor-surfacing belt is represented at 48. This belt may be made of sandpaper or other abrading material, or of carpeting or other polishing material, accordingly as the machine is to be used for removing paint or leveling and smoothing, by sandpapering away the paint or sandpapering otf the rough, protruding, or uneven parts of flooring, or as said machine is to be used for polishing a floor after oil, wax, or other polishing material has been applied thereto. The term floor-surfacing as applied to the belt 48 is to be understood as applying to any belt or equivalent element that may be used in the machine on the carrier 24. The belt 48 must be flexible and capable of being propelled by and with the carrier 24.

The belt 48 may be slipped onto and off of the carrier 24 from either side of the machine. This is done while the tension device for the belt 48, which device is described below, is swung downwardly into inoperative position. By means of the aforesaid tension device the belt 48 is held taut and caused to contact forcibly with three sides or reaches of the carrier 24, that is to say, with the top, bottom, and front reaches of said carrie'r. Obviously the carrier 24 may be slipped onto and off of the rollers 20 also from either side of the machine.

The tension device, of which mention has just been made, comprises a roller 49, front and rear supporting arms 50 and 51, respectively, for said roller, a rock-shaft 52 journaled in the front and back plates 1 and 2, said arms being rigidly attached to said rock-shaft, an operating arm or lever 53 also rigidly attached to said rock-shaft, a toothed sector 54 for said operating arm, a bearing extension 55 pivotally connected at 56 with said arm 50, upper and under adjusting screws 57-57 carried by said extension, and a pin 58 and a binding screw 59 carried by said arm 50. Each of the plates 1 and 2 has a recess 60 in its outer face and opening through the rear edge of the plate, to accommodate the contiguous arm 50 or 51 in such a manner that neither projects be yond the outer face of its contiguous plate. The arm 53 is resilient and carries at its free end a forwardly-extending knob 61. On the inner side adjacent to the free terminal of the arm 53 is a tooth 62 that is adapted to engage any of the sector teeth 54. The construction and arrangement of the teeth 54 and the tooth 62 are such that, when the arm 53 is swung upwardly, its tooth clicks past the sector teeth, and, when said arm is released, said tooth engages one of said sector teeth to hold said arm against downward movement or prevent the same from being swung downwardly. Upon draining the free terminal of the arm 53 forwardly far enough to disengage the tooth 62 from the engaged tooth 54, said arm can be swung downwardly, when, upon the release of said arm, said tooth 62 engages another one of the teeth 54. The arm 53 is operated by grasping the knob 61. Any movement of the arm 53 is imparted, through the medium of the rock-shaft 52, to the arms 50 and 51. When, therefore, the operating arm 58 is moved upwardly the bearing and supporting arms 50 and 51 are moved downwardly and carry with them the roller 49 against the adjacent reach ofthe belt carrier 24, and when said operating arm is moved downwardly said bearing and supporting arms are moved upwardly. If the belt 48 be in place on the machine when the arms 50 and 51 carry the roller 49 upwardly, said roller contacts with and stretches said belt or causes the same to become taut under the required amount of tension, and said roller n'i-aintains said belt in such condition until said arms are swung downwardly again. The belt 48 is slipped onto and off of the machine while the roller 49 is in its low position.

The roller 49 may be provided at each end with a disc 64 which extends beyond the periphery of said roller to assist in guiding the adjacent edge of the belt 48. The arm 51 is provided with an inwardlyextending pin 65 and the bearing extension 55 is provided with a similar pin. The discs 64 have hubs which enter axial openings in the ends of the roller 49, one of such hubs appearing at 66 in Fig. 1, and this hub flares at the inner terminal to afford a loose hearing or journal for the pin 65 which enters said hub, whereby a limited amount of motion of the roller 49 on said pin as a fulcrum is permitted. The other disc hubs forms a hearing or journal for the front pin 65. v

The bearing extension 55 has a vertical slot 67 and an arcuate slot 68 therein. The

pin 58 extends from the arm 50 into the slot 67, and the adjusting screws 57 are tapped into the parts of the bearing extension 55 which form the top and bottom of the slot 67. That part of the pin 58 which is in the slot 67 is between the inner ends of the screws 57. Obviously, there fore, if the screws 57 be rotated in the direction to move them downwardly, the hearing extension 55 is swung upwardly on its pivot 56, and, if said screws be rotated in the direction to move them upwardly, said extension is swung downwardly on said pivot. Although the screws 57 might be depended on to retain the extension 55 in position after adjustment by said screws, I prefer to employ in addition the binding screw 59. This screw passes through the slot 68 and is tapped into the arm 50. The screw 59 is loosened before the extension 55 is adjusted by means of the screws 57 that at their inner ends engage said pin, and then said first-named screw is set up tight against said extension to assist in holding the same in place and relieve said screws 57 of some of the strain.

The means described above for tilting the guide roller 49 afford the necessary adjustment for the floor-surfacing belt 48 in order to prevent the same when in motion from running off of the belt carrier 24. I have found that, without some adjustable, guiding means of this character, the moving belt 48 can be maintained in its true course, but creeps off over one edge or the other of the carrier 24. To overcome this tendency it is essential that there be provided a guide member, such as the roller 49, which is capable of exerting pressure on a part of the belt 48 that otherwise would be slack, and of inclining such part transversely of the belt, thereby increasing the tension on said belt at one edge or the other, as may be needed.

The belt carrier 24, being made of rubber and mounted directly on the rollers 20,

has no tendency to creep to one side andrun off of said rollers, but it is different with the floor-surfacing belt 48 which is supported directly on said carrier and thereby assisted torun off at one side or the other, in the absence of adjustable guide means. 7

It is desirable to provide yielding means forcibly to hold against the floor the reaches of the belt carrier 24 and the floor-surfacing belt 48 which are between the bottom r ll rs 20, and to this end I m y proshoes 69 are on opposite sides of t e reach of the driving strip 25 that extends between the bottom rollers 20. Four, more or less, springs 70 are interposed between the floor plate 3 and each shoe 69, and the latter is provided with a pair of bolts 71. Each bolt 71 passes upwardly through an opening 1n the plate 3 and has a nut 72 screwed onto the upper terminal thereof. The springs 70 are set in recesses 73 in the top of each shoe 69, and the tops of said springs are received in recesses 74 in the under side of the plate 3. Countersunk opemngs 7575 are formed in each shoe 69 for the bolts 71. The springs 70 force the shoes 69 onto the belt carrier 24 and floor-surfacing belt 48 and press the same onto the floor, or, in any event, prevent the reaches of said carrier and belt which are between the bottom rollers 20 from drawmg or being drawn upwardly between said rollers. Full contact of that part of the belt 48 which is beneath and between the bottom rollers 20 with the floor is thus obtained and insured. The bolts 71 prevent -the shoes 69 from being carried along with the carrier 24, and the nuts 72 prevent said bolts from becoming disengaged from the plate 3 in the event the machine be lifted at a time when there is no carrier on the rollers 20. The nuts 72 may also be employed for the purpose of drawing the bolts 71 upwardly, and with them the shoes 69, against the resiliency of the springs 70, when the carrier 24 is removed or replaced.

The arms 16 of the handle 15 are sufficiently resilient to enable them to be disengaged from the studs 14. This is a necessary provision because the handle 15 must be removed from the frame of the machine whenever a floor-surfacing belt is to be slipped on into place or removed, and, also, in the event it be necessary to take off and put on the belt carrier 24. If the endless traveling members he slipped on and off at the back side of the machine, it is not necessary to disengage the wires 45, but only the handle 15.

From the foregoing the operation of the floor surfacer as a whole will be quite well understood, hence I will only briefly describe such operation.

Assuming that the machine is e nipped and adjusted ready for use, and in p ace on the floor, the handle 15 is grasped, and the switch 46 is operated to'turn on the current, which sets in motion the motor shaft 18.

Motion from the shaft 18 is transmitted, through the intervening gears to the upper front roller 20, and said roller causes the belt carrier 24 and with it the floor-surfacing belt 48 to travel in their circuitous paths. The movement of the belt 48 on the floor causes the machine to move forwardly, but the operator holds the machine back or under restraint by means of the handle 15, and thus enables said belt to act or operate on the floor beneath. The operator guides the machine and permits it to move forward, but at a slower rate than it would travel if propelled by the belt 48 in the ab sence of any restraining influence. With the belt 48 running and the machine retarded and guided b the operator, the entire surface of the cor is operated on until the same is surfaced or resurfaced if the belt 48 be an abrading belt, or pohshed, if the belt 48 be a polishing belt. The machine is capable of acting on practically the entire area of the floor, the only portions of said floor that said machine can not be actively brought into contact with being the portions immediately adjacent to the baseboards and equal in width to the thickness of the back plate 2. By holding the machine stationary it is caused to rub down or grind off only the portion of the floor which is covered by the bottom reach of the belt 48, wherefore said machine is or may be made to operate longer on some portions of the floor than on others, according to the exigencies of the case or as the nature of the work demands.

When it is desired to stop the machine, the switch 46 is actuated in the direction opposite to that in which it was actuated to start the machine.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The combination, in a floor surfacer, with a slotted frame, bars held and arranged to slide in the slots in said frame, and rigid connecting means between said bars, of a shaft journaled in said frame, a ratchetwheel and a cam secured to said shaft said connecting means being in the path of said cam, and a pawl pivotally connected with said frame for said ratchet-wheel.

2. The combination, in a floor surfacer, with a slotted frame, bars held and arranged to slide in the slots in said frame, and rigid connecting means between said bars, of a shaft journaled in said frame, a ratchetwheel and a cam secured to said shaft, said connecting-means being in the path of said cam, a spindle journaled in said frame, and a pawl secured to said spindle for said ratchet-wheel, said shaft and spindle being provided outside of said frame with knobs,

' In a floorsurfacena frame. provided with rollers, .aflbelt carrieron said rol1ers,'.

means" to adjust one of said rollers in 8.

straight path to vary the .tension of said carrier, a floor-surfacing belt on said carrier, guiding means for said belt, means to adjust said guiding means in an arcuate path to vary the tension of said belt, and

means further to adjust said guiding means at one end to vary the tension on opposite side portions of said belt.

4. The combination, in a floor surfacer, with a frame provided on one side with engageing means, and with horizontal rollers, and a belt carrier on said rollers, of a horizontal rock-shaft journaled at opposite terminals in the sides of said frame, arms secured to and extended rearwardly from said rockshaft, a roller carried by said arms, a floorsurfacing belt mounted outside of said carrier and passing over said last-named roller, and an operating arm secured to said rock-shaft and adapted to cooperate with said engaging means for the purpose of positively locking and releasing said rock-shaft.

5. The combination, in a fioor surfacer, with a frame provided with teeth and with rollers, and a belt carrier on said rollers, of a rock-shaft journaled in said frame, arms secured to said rock-shaft, a roller carried by said arms, a floor-surfacing belt mounted outside of said carrier and passing over said last-named roller, and a resilient arm secured to said rock-shaft and having a tooth to engage the frame teeth.

6. The combination, in a floor surfacer, with a frame provided with rollers, and a belt carrier on said rollers, of oscillatory arms connected with said frame, positive locking and releasing means for said arms, a member pivotally connected with one of said arms, adjustable means for said member, a roller supported directly by the other of said arms and by said member, and a floor-surfacing belt mounted outside of said carrier and passing over said last-named roller.

7. The combination, in a floor surfacer,

with a frame provided with rollers, and abelt carrieron said rollers, of a rock-shaft journaled in said frame, positive locking and releasing means for said rock-shaft, arms secured to said rock-shaft, one of said arms having a pin, a slotted bearing extension pivotally connected with such arm and receiving said pin in one of the slots therein, screws carried by said extension to engage said pin from opposite directions, a binding screw passing through the other slot in said extension into said arm, a roller supported directly by the other of said arms and by said extension, and a floor-surfacing belt mounted outside of said carrier and passing over said last-named roller.

.8. In a floor. surfacer, a frame, rollers mounted in said'frame, one of said rollers havin a gear of less width than the length of Sue rolle a belt carrier on. said roller and provided with a flexible toothed driving member of a width to engage said gear, and means to drive said rollers.

9. In a floor surfacer,- a frame, rollers mounted on said frame, one of said rollers having a gear of less width than the length of such roller, a belt carrier on said rollers and provided with a flexible toothed driving member of a width to engage said gear, the other rollers being grooved to permit said member to pass as said carrier travels over the same, and means to drive said gear.

10. In a floor surfacer, a frame, rollers mounted in said frame, one of said rollers being provided with gears each of which is narrow compared with the length of said roller, a belt carrier on said rollers and equipped with a flexible toothed driving member of a width to engage one of said gears, a motor supported by said frame, and a train of gears between said motor and the other of said gears.

11. In a floor surfacer, a frame comprising side and bottom members, the bottom member being above the lower edges of the side members, rollers mounted in said side members, a motor supported by said bottom member, means to drive one of said rollers from said motor, a belt carrier on said rollers, said carrier passing under said bottom member, a shoe between said bottom member and said carrier, and means interposed between said bottom member and said shoe to force the latter against the carrier.

12. In a floor surfacer, a frame comprising rigidly-connected side and bottom members, the bottom member being above the lower edges of the side members, rollers mounted in said side members, a belt carrier on said rollers and passing under said bottom member, a motor supported by said bottom member, means to drive said carrier from said motor, a shoe between said bottom member and said carrier, and means interposed between said bottom member and said shoe .to force the latter against said carrier.

13. In a floor surfacer, a frame'comprising side and bottom members, the bottom member being above the lower edges of and extending between the side members L0 which the former is secured, rollers mounted in said side members, a belt carrier on said rollers, said carrier being equipped inside with a toothed driving member, and downwardly spring-pressed shoes between said bottom member and said carrier, said shoes being spaced apart to receive between them said driving member.

14. In a floor surfacer, a frame comprising side and bottom members, the bottom.

member being above the lower edges of, extending between, and secured to the side members, rollers mounted in said frame, a belt carrier on said rollers, a shoe between said bottom member and said carrier, springs arranged between said bottom member and said shoe to force the latter downwardly, and means to prevent said shoe from moving with said carrier. I

15. In a floor surfacer, a frame comprising side and bottom members, the bottom member being above the lower edges of, extending between, and secured to the side members, rollers mounted in said side members, a belt carrier on said rollers, a shoe, springs arranged between said bottom member and said shoe to force the latter downwardly, and members rising from said shoe and passing through said bottom member to prevent said shoe from moving with said carrier, and having enlarged parts above the bottom member to prevent the upstandin'g members from becomin disengaged from the bottom member in t e absence of said belt carrier.

' WILLIAM A. LACY. 

